The whole placenta, after dissection from the uterus in mid-gestation, contains both a fetal component (the placenta proper, consisting of the labyrinth, spongiotrophoblast and giant cell layers) and a maternal component (the decidua basalis, as well as maternal blood vessels).

However, in their studies the major decoy receptor for TRAIL, DcR1, was found expressed in trophoblast, not in decidua, while another decoy receptor, DcR2, was expressed by placental macrophages.

Microglial cells are resident macrophages in the central nervous system, and LHR expression has been described in other types of human resident macrophages (ovary, decidua, endometrium and corpora lutea) [ 22 33 ] . Pathological activation of microglia has been reported in a wide range of conditions such as Alzheimer's disease, cerebral ischemia, prion diseases, multiple sclerosis, AIDS dementia, and other degenerative neurological diseases [ 70 71 ] . Some of these degenerative diseases are associated with advanced age and high levels of circulating LH.